1887, pre-printed cover of ''Airship the Construction Department. Russia'' (The Head of the Department was Prof. Dmitry I. Mendeleyev, creator of the Periodic Law of Elements), the item franked by 7k blue and sent from St. Petersburg to Berlin, addressed to Hermann Moedebeck, Aeronautics Pioneer, specialist in air navigation, the cover has all appropriate markings, VF, a rarity the dawn of aviation, Est. $3,000-$4,000 (Image)

1923, red Airplane overprint on 45r green and black in vertical pair together with 28 other RSFSR adhesives and two exchange tax stamps used on registered cover from Moscow to US, all appropriate markings and NYC arrival ds, minor wearing, still F/VF and rare mailing, Est. $300-$400 (Image)

1928, two Soviet Trade Mission in Germany pre-printed flown covers from Berlin to Moscow, beautiful German machine postage imprint, appropriate Air Post labels and arrival ds on reverse, placed on the Collection page, mostly VF, ex-V. Ustinovsky, Est. $150-$200 (Image)

1933, Stratostat USSR-1, 5k, 10k and 20k, complete set of three, full OG, NH, VF, C.v. $463, Est. $250-$300 (Image)

1934, Civil Aviation, trial color imperforated proof of 5k in brown with pale brown background, printed on watermarked Borders and Rosettes paper, full OG, NH, VF, Est. $800-$1,000 (Image)

1934, Civil Aviation, 80k purple, a single with perforation 10x13¾x13¾x13¾, printed on watermarked Borders and Rosettes paper, rough perforation at top as typical for these errors, neat Moscow CTO with full OG, VF and rare, N. Mandrovski certificate, Est. $1,500-$2,000 (Image)

1935, Moscow - San Francisco Flight, red surcharge 1r on 10k dark brown, small ''f'' in San Francisco variety (position 7), large part of OG (gum lost at bottom left corner), VF, Soviet Philatelic guarantee hs, V. Zagorsky certificate, C.v. $1,500, Est. $700-$800 (Image)

1955, Moscow - North Pole Flight, red overprints on 1r and 2r, complete set of two, each one without dash variety, full OG, NH, VF, Est. $300-$400 (Image)